gtkcurve.c

gtk是linux一款强大的夸平台的图形化开发工具

/* GTK - The GIMP Toolkit
 * Copyright (C) 1997 David Mosberger
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

/*
 * Modified by the GTK+ Team and others 1997-1999.  See the AUTHORS
 * file for a list of people on the GTK+ Team.  See the ChangeLog
 * files for a list of changes.  These files are distributed with
 * GTK+ at ftp://ftp.gtk.org/pub/gtk/. 
 */

#include <stdlib.h>
#include <string.h>
#include <math.h>

#include "gtkcurve.h"
#include "gtkdrawingarea.h"
#include "gtkmain.h"
#include "gtkradiobutton.h"
#include "gtksignal.h"
#include "gtktable.h"

#define RADIUS		3	/* radius of the control points */
#define MIN_DISTANCE	8	/* min distance between control points */

#define GRAPH_MASK	(GDK_EXPOSURE_MASK |		\
			 GDK_POINTER_MOTION_MASK |	\
			 GDK_POINTER_MOTION_HINT_MASK |	\
			 GDK_ENTER_NOTIFY_MASK |	\
			 GDK_BUTTON_PRESS_MASK |	\
			 GDK_BUTTON_RELEASE_MASK |	\
			 GDK_BUTTON1_MOTION_MASK)

enum {
  ARG_0,
  ARG_CURVE_TYPE,
  ARG_MIN_X,
  ARG_MAX_X,
  ARG_MIN_Y,
  ARG_MAX_Y
};

static GtkDrawingAreaClass *parent_class = NULL;
static guint curve_type_changed_signal = 0;


/* forward declarations: */
static void gtk_curve_class_init   (GtkCurveClass *class);
static void gtk_curve_init         (GtkCurve      *curve);
static void gtk_curve_set_arg     (GtkObject      *object,
				   GtkArg         *arg,
				   guint           arg_id);
static void gtk_curve_get_arg     (GtkObject      *object,
				   GtkArg         *arg,
				   guint           arg_id);
static void gtk_curve_finalize     (GtkObject     *object);
static gint gtk_curve_graph_events (GtkWidget     *widget, 
				    GdkEvent      *event, 
				    GtkCurve      *c);
static void gtk_curve_size_graph   (GtkCurve      *curve);

GtkType
gtk_curve_get_type (void)
{
  static GtkType curve_type = 0;

  if (!curve_type)
    {
      static const GtkTypeInfo curve_info =
      {
	"GtkCurve",
	sizeof (GtkCurve),
	sizeof (GtkCurveClass),
	(GtkClassInitFunc) gtk_curve_class_init,
	(GtkObjectInitFunc) gtk_curve_init,
	/* reserved_1 */ NULL,
        /* reserved_2 */ NULL,
        (GtkClassInitFunc) NULL,
      };

      curve_type = gtk_type_unique (GTK_TYPE_DRAWING_AREA, &curve_info);
    }
  return curve_type;
}

static void
gtk_curve_class_init (GtkCurveClass *class)
{
  GtkObjectClass *object_class;
  
  parent_class = gtk_type_class (GTK_TYPE_DRAWING_AREA);
  
  object_class = (GtkObjectClass *) class;
  
  object_class->set_arg = gtk_curve_set_arg;
  object_class->get_arg = gtk_curve_get_arg;
  object_class->finalize = gtk_curve_finalize;
  
  curve_type_changed_signal =
    gtk_signal_new ("curve_type_changed", GTK_RUN_FIRST, object_class->type,
		    GTK_SIGNAL_OFFSET (GtkCurveClass, curve_type_changed),
		    gtk_marshal_NONE__NONE, GTK_TYPE_NONE, 0);
  gtk_object_class_add_signals (object_class, &curve_type_changed_signal, 1);
  
  gtk_object_add_arg_type ("GtkCurve::curve_type", GTK_TYPE_CURVE_TYPE,
			   GTK_ARG_READWRITE, ARG_CURVE_TYPE);
  gtk_object_add_arg_type ("GtkCurve::min_x", GTK_TYPE_FLOAT,
			   GTK_ARG_READWRITE, ARG_MIN_X);
  gtk_object_add_arg_type ("GtkCurve::max_x", GTK_TYPE_FLOAT,
			   GTK_ARG_READWRITE, ARG_MAX_X);
  gtk_object_add_arg_type ("GtkCurve::min_y", GTK_TYPE_FLOAT,
			   GTK_ARG_READWRITE, ARG_MIN_Y);
  gtk_object_add_arg_type ("GtkCurve::max_y", GTK_TYPE_FLOAT,
			   GTK_ARG_READWRITE, ARG_MAX_Y);
}

static void
gtk_curve_init (GtkCurve *curve)
{
  gint old_mask;

  curve->cursor_type = GDK_TOP_LEFT_ARROW;
  curve->pixmap = NULL;
  curve->curve_type = GTK_CURVE_TYPE_SPLINE;
  curve->height = 0;
  curve->grab_point = -1;

  curve->num_points = 0;
  curve->point = 0;

  curve->num_ctlpoints = 0;
  curve->ctlpoint = NULL;

  curve->min_x = 0.0;
  curve->max_x = 1.0;
  curve->min_y = 0.0;
  curve->max_y = 1.0;

  old_mask = gtk_widget_get_events (GTK_WIDGET (curve));
  gtk_widget_set_events (GTK_WIDGET (curve), old_mask | GRAPH_MASK);
  gtk_signal_connect (GTK_OBJECT (curve), "event",
		      (GtkSignalFunc) gtk_curve_graph_events, curve);
  gtk_curve_size_graph (curve);
}

static void
gtk_curve_set_arg (GtkObject *object,
		   GtkArg    *arg,
		   guint      arg_id)
{
  GtkCurve *curve = GTK_CURVE (object);
  
  switch (arg_id)
    {
    case ARG_CURVE_TYPE:
      gtk_curve_set_curve_type (curve, GTK_VALUE_ENUM (*arg));
      break;
    case ARG_MIN_X:
      gtk_curve_set_range (curve, GTK_VALUE_FLOAT (*arg), curve->max_x,
			   curve->min_y, curve->max_y);
      break;
    case ARG_MAX_X:
      gtk_curve_set_range (curve, curve->min_x, GTK_VALUE_FLOAT (*arg),
			   curve->min_y, curve->max_y);
      break;	
    case ARG_MIN_Y:
      gtk_curve_set_range (curve, curve->min_x, curve->max_x,
			   GTK_VALUE_FLOAT (*arg), curve->max_y);
      break;
    case ARG_MAX_Y:
      gtk_curve_set_range (curve, curve->min_x, curve->max_x,
			   curve->min_y, GTK_VALUE_FLOAT (*arg));
      break;
    }
}

static void
gtk_curve_get_arg (GtkObject *object,
		   GtkArg    *arg,
		   guint      arg_id)
{
  GtkCurve *curve = GTK_CURVE (object);

  switch (arg_id)
    {
    case ARG_CURVE_TYPE:
      GTK_VALUE_ENUM (*arg) = curve->curve_type;
      break;
    case ARG_MIN_X:
      GTK_VALUE_FLOAT (*arg) = curve->min_x;
      break;
    case ARG_MAX_X:
      GTK_VALUE_FLOAT (*arg) = curve->max_x;
      break;
    case ARG_MIN_Y:
      GTK_VALUE_FLOAT (*arg) = curve->min_y;
      break;
    case ARG_MAX_Y:
      GTK_VALUE_FLOAT (*arg) = curve->max_y;
      break;
    default:
      arg->type = GTK_TYPE_INVALID;
      break;
    }
}

static int
project (gfloat value, gfloat min, gfloat max, int norm)
{
  return (norm - 1) * ((value - min) / (max - min)) + 0.5;
}

static gfloat
unproject (gint value, gfloat min, gfloat max, int norm)
{
  return value / (gfloat) (norm - 1) * (max - min) + min;
}

/* Solve the tridiagonal equation system that determines the second
   derivatives for the interpolation points.  (Based on Numerical
   Recipies 2nd Edition.) */
static void
spline_solve (int n, gfloat x[], gfloat y[], gfloat y2[])
{
  gfloat p, sig, *u;
  gint i, k;

  u = g_malloc ((n - 1) * sizeof (u[0]));

  y2[0] = u[0] = 0.0;	/* set lower boundary condition to "natural" */

  for (i = 1; i < n - 1; ++i)
    {
      sig = (x[i] - x[i - 1]) / (x[i + 1] - x[i - 1]);
      p = sig * y2[i - 1] + 2.0;
      y2[i] = (sig - 1.0) / p;
      u[i] = ((y[i + 1] - y[i])
	      / (x[i + 1] - x[i]) - (y[i] - y[i - 1]) / (x[i] - x[i - 1]));
      u[i] = (6.0 * u[i] / (x[i + 1] - x[i - 1]) - sig * u[i - 1]) / p;
    }

  y2[n - 1] = 0.0;
  for (k = n - 2; k >= 0; --k)
    y2[k] = y2[k] * y2[k + 1] + u[k];

  g_free (u);
}

static gfloat
spline_eval (int n, gfloat x[], gfloat y[], gfloat y2[], gfloat val)
{
  gint k_lo, k_hi, k;
  gfloat h, b, a;

  /* do a binary search for the right interval: */
  k_lo = 0; k_hi = n - 1;
  while (k_hi - k_lo > 1)
    {
      k = (k_hi + k_lo) / 2;
      if (x[k] > val)
	k_hi = k;
      else
	k_lo = k;
    }

  h = x[k_hi] - x[k_lo];
  g_assert (h > 0.0);

  a = (x[k_hi] - val) / h;
  b = (val - x[k_lo]) / h;
  return a*y[k_lo] + b*y[k_hi] +
    ((a*a*a - a)*y2[k_lo] + (b*b*b - b)*y2[k_hi]) * (h*h)/6.0;
}

static void
gtk_curve_interpolate (GtkCurve *c, gint width, gint height)
{
  gfloat *vector;
  int i;

  vector = g_malloc (width * sizeof (vector[0]));

  gtk_curve_get_vector (c, width, vector);

  c->height = height;
  if (c->num_points != width)
    {
      c->num_points = width;
      if (c->point)
	g_free (c->point);
      c->point = g_malloc (c->num_points * sizeof (c->point[0]));
    }

  for (i = 0; i < width; ++i)
    {
      c->point[i].x = RADIUS + i;
      c->point[i].y = RADIUS + height
	- project (vector[i], c->min_y, c->max_y, height);
    }

  g_free (vector);
}

static void
gtk_curve_draw (GtkCurve *c, gint width, gint height)
{
  GtkStateType state;
  GtkStyle *style;
  gint i;

  if (!c->pixmap)
    return;

  if (c->height != height || c->num_points != width)
    gtk_curve_interpolate (c, width, height);

  state = GTK_STATE_NORMAL;
  if (!GTK_WIDGET_IS_SENSITIVE (GTK_WIDGET (c)))
    state = GTK_STATE_INSENSITIVE;

  style = GTK_WIDGET (c)->style;

  /* clear the pixmap: */
  gtk_paint_flat_box (style, c->pixmap, GTK_STATE_NORMAL, GTK_SHADOW_NONE,
		      NULL, GTK_WIDGET(c), "curve_bg",
		      0, 0, width + RADIUS * 2, height + RADIUS * 2);
  /* draw the grid lines: (XXX make more meaningful) */
  for (i = 0; i < 5; i++)
    {
      gdk_draw_line (c->pixmap, style->dark_gc[state],
		     RADIUS, i * (height / 4.0) + RADIUS,
		     width + RADIUS, i * (height / 4.0) + RADIUS);
      gdk_draw_line (c->pixmap, style->dark_gc[state],
		     i * (width / 4.0) + RADIUS, RADIUS,
		     i * (width / 4.0) + RADIUS, height + RADIUS);
    }

  gdk_draw_points (c->pixmap, style->fg_gc[state], c->point, c->num_points);
  if (c->curve_type != GTK_CURVE_TYPE_FREE)
    for (i = 0; i < c->num_ctlpoints; ++i)
      {
	gint x, y;

	if (c->ctlpoint[i][0] < c->min_x)
	  continue;

	x = project (c->ctlpoint[i][0], c->min_x, c->max_x,
		     width);
	y = height -
	  project (c->ctlpoint[i][1], c->min_y, c->max_y,
		   height);

	/* draw a bullet: */
	gdk_draw_arc (c->pixmap, style->fg_gc[state], TRUE, x, y,
		      RADIUS * 2, RADIUS*2, 0, 360*64);
      }
  gdk_draw_pixmap (GTK_WIDGET (c)->window, style->fg_gc[state], c->pixmap,
		   0, 0, 0, 0, width + RADIUS * 2, height + RADIUS * 2);
}

static gint
gtk_curve_graph_events (GtkWidget *widget, GdkEvent *event, GtkCurve *c)
{
  GdkCursorType new_type = c->cursor_type;
  gint i, src, dst, leftbound, rightbound;
  GdkEventButton *bevent;
  GdkEventMotion *mevent;
  GtkWidget *w;
  gint tx, ty;
  gint cx, x, y, width, height;
  gint closest_point = 0;
  gfloat rx, ry, min_x;
  guint distance;
  gint x1, x2, y1, y2;

  w = GTK_WIDGET (c);
  width = w->allocation.width - RADIUS * 2;
  height = w->allocation.height - RADIUS * 2;

  if ((width < 0) || (height < 0))
    return FALSE;

  /*  get the pointer position  */
  gdk_window_get_pointer (w->window, &tx, &ty, NULL);
  x = CLAMP ((tx - RADIUS), 0, width-1);
  y = CLAMP ((ty - RADIUS), 0, height-1);

  min_x = c->min_x;

  distance = ~0U;
  for (i = 0; i < c->num_ctlpoints; ++i)
    {
      cx = project (c->ctlpoint[i][0], min_x, c->max_x, width);
      if ((guint) abs (x - cx) < distance)
	{
	  distance = abs (x - cx);
	  closest_point = i;
	}
    }

  switch (event->type)
    {
    case GDK_CONFIGURE:
      if (c->pixmap)
	gdk_pixmap_unref (c->pixmap);
      c->pixmap = 0;
      /* fall through */
    case GDK_EXPOSE:
      if (!c->pixmap)
	c->pixmap = gdk_pixmap_new (w->window,
				    w->allocation.width,
				    w->allocation.height, -1);
      gtk_curve_draw (c, width, height);
      break;

    case GDK_BUTTON_PRESS:
      gtk_grab_add (widget);

      bevent = (GdkEventButton *) event;
      new_type = GDK_TCROSS;

      switch (c->curve_type)
	{
	case GTK_CURVE_TYPE_LINEAR:
	case GTK_CURVE_TYPE_SPLINE:
	  if (distance > MIN_DISTANCE)
	    {
	      /* insert a new control point */
	      if (c->num_ctlpoints > 0)
		{
		  cx = project (c->ctlpoint[closest_point][0], min_x,
				c->max_x, width);
		  if (x > cx)
		    ++closest_point;
		}
	      ++c->num_ctlpoints;
	      c->ctlpoint =
		g_realloc (c->ctlpoint,
			   c->num_ctlpoints * sizeof (*c->ctlpoint));
	      for (i = c->num_ctlpoints - 1; i > closest_point; --i)
		memcpy (c->ctlpoint + i, c->ctlpoint + i - 1,
			sizeof (*c->ctlpoint));
	    }
	  c->grab_point = closest_point;
	  c->ctlpoint[c->grab_point][0] =
	    unproject (x, min_x, c->max_x, width);
	  c->ctlpoint[c->grab_point][1] =
	    unproject (height - y, c->min_y, c->max_y, height);

	  gtk_curve_interpolate (c, width, height);
	  break;

	case GTK_CURVE_TYPE_FREE:
	  c->point[x].x = RADIUS + x;
	  c->point[x].y = RADIUS + y;
	  c->grab_point = x;
	  c->last = y;
	  break;
	}
      gtk_curve_draw (c, width, height);
      break;

    case GDK_BUTTON_RELEASE:
      gtk_grab_remove (widget);

      /* delete inactive points: */